Positioning systems can utilize various types of information to calculate location of an object. Such information can include dead reckoning calculations that can utilize sensor information from the device to be located. For example, an indoor positioning system may use dead reckoning calculations based on sensor data gathered from a user's cell phone to determine the location of the user within a building. Unfortunately, these sensors can consume a lot of power, which can be a problem for cell phones and other mobile devices with a limited power budget. Furthermore data from certain sensors may not be particularly useful to determine certain types of motion.